Delta (letter)
Delta (/ˈdɛltə/;[1] uppercase Δ, lowercase δ; Greek: δέλτα, délta, [ˈðelta])[2] is the fourth letter of the Greek alphabet. In the system of Greek numerals it has a value of 4. It was derived from the Phoenician letter dalet 𐤃.[3] Letters that come from delta include Latin D and Cyrillic Д.
"Δ" redirects here. For other uses, see ∆ (disambiguation).A river delta (originally, the delta of the Nile River) is so named because its shape approximates the triangular uppercase letter delta. Contrary to a popular legend, this use of the word delta was not coined by Herodotus.[4]
Pronunciation[edit]
In Ancient Greek, delta represented a voiced dental plosive IPA: [d]. In Modern Greek, it represents a voiced dental fricative IPA: [ð], like the "th" in "that" or "this" (while IPA: [d] in foreign words is instead commonly transcribed as ντ). Delta is romanized as d or dh.
Change of any changeable quantity, in mathematics and the sciences (in particular, the [5][6]); for example, in the average change of y per unit x (i.e. the change of y over the change of x). Delta is the initial letter of the Greek word διαφορά diaphorá, "difference". (The small Latin letter d is used in much the same way for the notation of derivatives and differentials, which also describe change by infinitesimal amounts.)
difference operator
The :
Laplace operator
The
area of a triangle
The uppercase letter Δ is used to denote:
The lowercase letter δ (or 𝛿) can be used to denote:
These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style.